With the development of display technology, the flat panel device, such as Liquid Crystal Display (LCD) possesses advantages of high image quality, power saving, thin body and wide application scope. Thus, it has been widely applied in various consumer electrical products, such as mobile phone, television, personal digital assistant, digital camera, notebook, laptop, and becomes the major display device.
Most of the liquid crystal displays on the present market are back light type liquid crystal displays, which comprise a liquid crystal display panel and a back light module. The working principle of the liquid crystal display panel is to locate liquid crystal molecules between two parallel glass substrates, and a plurality of vertical and horizontal tiny electrical wires are between the two glass substrates. The light of back light module is reflected to generate images by applying driving voltages to control whether the liquid crystal molecules to be changed directions.
Generally, the liquid crystal display panel comprises a CF (Color Filter) substrate, a TFT (Thin Film Transistor) substrate, LC (Liquid Crystal) sandwiched between the CF substrate and TFT substrate and sealant. The formation process generally comprises: a forepart Array process (thin film, photo, etching and stripping), a middle Cell process (Lamination of the TFT substrate and the CF substrate) and a post module assembly process (Attachment of the driving IC and the printed circuit board). The forepart Array process is mainly to form the TFT substrate for controlling the movement of the liquid crystal molecules; the middle Cell process is mainly to add liquid crystal between the TFT substrate and the CF substrate; the post module assembly process is mainly the driving IC attachment and the integration of the printed circuit board. Thus, the liquid crystal molecules are driven to rotate and display pictures.
With the constant development of the liquid crystal panel technology, more and more new technologies have been applied in the thin film transistor array substrate, such as In-Plane Switching (IPS), Fringe Field Switching (FFS), Color Filter On Array (COA) and et cetera. These technologies have higher demands for the flatness of the display substrate and generally, an organic layer, such as a color resist layer, a flat layer, which is thicker is required to be deposed on the array substrate. During the manufacture process of the array substrate, there may be broken line situations happening to the metal lines, including the scan lines and the data lines due to the effects of various reasons. For repairing such broken lines of the array substrate, the laser welding is utilized for repairing the broken line position after the broken line repairer removes the organic layer and the transparent electrode, first. The broken line repair takes a lot of time. When the organic layer cannot be completely removed, it can affect the broken line repair success rate of the product.